颅底及面部骨纤维病变的影像学分析

目的 探讨颅底及面部骨纤维病变的CT和MRI诊断及鉴别诊断价值,提出术后影像学随访的重要性. 资料与方法回顾性分析经临床病理和组织学活检证实的颅底及面部20例骨化性纤维瘤和23例骨纤维发育不良患者的CT和MR影像学资料,并对两类病变共计27例进行术后影像随访.结果 20例骨化性纤维瘤中,18例为单骨发病,2例为多骨病变.CT表现为椭圆形或分叶状稍高密度肿块,边界清晰,瘤周有一层较完整或不完整的骨性包壳.内部呈不均匀密度13例,均匀磨玻璃样密度7例,其中11例有明显囊变坏死区;11例MR T_1WI以等、低信号为主,T_2WI以等、高信号为主,11例增强后间隔和实性部分强化.23例骨纤维发育不良中,多骨型20例,单骨型3例,无明确边界,密度均匀或不均匀,骨皮质变薄、模糊,骨质周围无软组织肿块和骨膜反应.5例MRT_1WI、T_2WI均以等、低信号为主,信号不均匀.结论 颅底及面部骨化性纤维瘤和骨纤维发育不良有相似的临床、病理特点,影像学有一定特征,有助于诊断和鉴别,部分病例两者鉴别困难.术后影像学随访以CT为主,MRI对需要再次手术者为重要补充.

Imaging Study of Fibrous Bone Lesion in the Skull Base and Craniofacial Region

Objective To investigate the value of CT and MR in the diagnosis of ossifying fibroma and fibrous dysplasia in the skull base and craniofacial region and to emphasis on the importance of the imaging follow-up.Materials and Methods CT and MRI data of 20 cases with ossifying fibroma and 23 cases with fibrous dysplasia confirmed pathologically were analyzed retrospectively.27 cases of the two groups after operation were followed up.Results Among the 20 cases of ossifying fibroma,the lesions occurred in monostotic in 18 cases,in ployostotic in 2 cases.On CT images,the lesions appeared as an ovoid or lobular,well-demarcated,higher soft-tissue attenuation with clearly margins.The tumor was usually surrounded by a sclerotic rim or shell that may be partially disrupted.On bone algorithm reconstruction of CT,The internal density of the tumors revealed heterogeneous low-attenuation areas in 13 cases,"ground-glass like"density masses in 7 cases compared with adjacent muscles.Among the 20 cases,11 lesions exhibited markedly cystic areas.On MR images,ossifying fibroma generally appeared hypointense or isointense on T_1WI and isointense or hyperintense on T_2WI relative to muscles.Solid portions and internal septa enhanced after gadolinium injection.Among the 23 cases of fibrous dysplasia,the lesions occurred in monostotic in 3 cases,in ployostotic in 20 cases.Fibrous dysplasia typically demonstrated a medullary-based lesion with expansible osseous remolding.A characteristic "ground-glass" appearance could be seen with diffuse and obscure margins.On MR images,5 lesions revealed isointense or hypointense on T_1WI and isointense or hyperintense on T_2WI respectively compared with adjacent muscles.Post-contrast MR images demonstrated heterogeneous enhancement.Conclusion Fibrous dysplasia and ossifying fibroma have the similar clinical and pathological findings,imaging features,which may be helpful in differential diagnosis.Occasionally,the differential diagnosis of some cases may be difficult.In the imaging follow-up,CT is the modality of fist choice and MRI regarded as a complemental method.